Why do we sleep?

Sleep. Most of us do it every day and it's a part of life. The average person needs 8 hours of sleep every night. There are plenty of animals that don't sleep at all, such as Jellyfish, Bullfrogs, Sea Urchins, and baby Dolphins. So, why do we sleep? There are two major types of sleep. REM sleep(Rapid Eye Movement) and Non-REM sleep. REM sleep has low amplitude and high-frequency EEG rhythms. Non-REM sleep has high amplitude and low-frequency EEG rhythms. Both happen when we are asleep and show us how we sleep but why we do is a completely different question. 

Scientists have tried to figure out exactly why we sleep but with fruitless attempts. Even though we are not sure about exactly why we sleep, we have discovered many promising theories. Let's take a look at a few of them.

Theory #1: Inactivity Theory

The Inactivity Theory is sometimes called the Adaptive or Evolutionary theory. The theory suggests that Inactivity/Sleeping at night caused organisms to stay out of harm's way. You may ask, "How does sleeping keep someone out of harm's way?" When organisms are inactive/sleeping, they are still and quiet causing predators in the area not to find them. Because of Natural Selection, this theory suggests that inactivity evolved into what's now known as sleep. 

Theory #2: Energy Conservation Theory

The Energy Conservation Theory suggests that organisms sleep at night to save food and energy. Although this might not be the reason for people that live in places with a lot of food, it could definitely apply to other places in our world. Research shows that energy metabolism decreases by 10% in humans. Many scientists think this theory is related to the inactivity theory.

Theory #3: Restorative Theories

The Restorative Theory suggests that sleeping could restore things we lost in our bodies. Sleep gives us an opportunity to restore and rejuvenate ourselves. This theory is supported by the fact that many of the major restorative functions in the body like muscle growth, tissue repair, and protein synthesis only occur during sleep. 

These are just a few out of many theories scientists have come up with. Even though we still don't know the exact reason to why we sleep, we have learned many things in the process. 

(Leave a Comment below on which theory might be the reason why we sleep!)

Works Cited

https://www.nature.com/articles/nn1200_1225

https://www.healthline.com/health/why-do-we-sleep#energy-conservation